Antistatic composition for synthetic fibers



United States Patent 3,395,107 ANTISTATIC COMPOSITION FOR SYNTHETIC FIBERS Edward Vernon Burnthall, 2305 College St.; Julian J.

Hirshfeld, 808 14th Ave. SE.; and Bertie J. Reuben, 614 Gordon Drive SE., all of Decatur, Ala. 35601 No Drawing. Filed July 6, 1964, Ser. No. 380,638

17 Claims. (Cl. 260-18) This invention relates to synthetic fibers having thereon an antistatic finish which minimizes the accumulation of charges of static electricity during normal use and finishing operations. More particularly, this invention relates to treated synthetic fibers which process readily through the usual operations of textile manufacture without the application of special processing agents and which have a resistance to the accumulation of static electricity which is not lost after repeating washings.

Synthetic fibers are at a distinct disadvantage when compared with natural fibers in one respect for synthetic fibers have the tendency to collect static electrical charges during the manufacture and wearing thereof. Finished synthetic textile fabrics fail to drape like cotton or wool due to the accumulation of the static charges thereon and have a tendency to cling uncomfortably to the wearer. The static charges also attract dust and lint to the fabric. It is well known in the art that polyamides are effective temporary antistatic agents but lack durability when washed and have the tendency to impart undesirable characteristics to the fiber to which they are applied, such as, unpleasant hand, discoloration and the like. The problem of durability may be eliminated if high molecular weight polyamines are created by polymerization on the surface of the fibers from lower polyamines and dihalogen compounds, but this it not practical for the high temperature required adversely afiects the fiber. Another more successful approach has been to cross-link the polyamines on the surface of the fiber by means of an epoxy resin. This approach has been successfully demonstrated when applied to the completed fabric and to a lesser degree when applied to finished fiber. A more desirable approach would be to apply the antistatic coating to the fiber during the spinning thereof but this has not proved feasible with typical polyamine/epoxy compositions because of the adhesive characteristics of the epoxy group.

Amine/epoxy compositions are known to be elfective adhesives and may be used for cementing together not only similar materials but such dissimilar materials such as metals, wood, fabric, glass, and rubber. When a polyamine/ epoxy composition of the prior art was applied in an aqueous suspension in a known manner to an acrylic fiber during the spinning operation, there was an extreme buildup of the polymerized polyamine/ epoxy material on the curing roll surfaces. Individual filaments were cemented together in bundles and the cementing of some of the filaments to the roll surfaces resulted in many broken filaments and wholly unsatisfactory spinning results.

Treatment of the finished fiber with the same polyamine/ epoxy composition and curing either by heat treatment or prolonged standing of the fiber under ambient conditions in staple form avoided the problems associated with application during the spinning of the fiber but gave a harsh fiber product which processed extremelypoorly on woolen system machinery and which showed high card loading that could not be corrected by the application of softeners, lubricants, or other finishing agents to the fiber.

Therefore, an object of this invention is to provide a novel process and composition of matter which will impart antistatic protection to a synthetic, hydrophobic 3,395,107 Patented July 30, 1968 ice shaped structure without causing objectionable changes in the properties thereof.

Another object of this invention is to provide a process which will continuously impart durable antistatic protection to a synthetic textile fiber during the manufacture thereof.

A further object of this invention is to provide a synthetic fiber having a durable antistatic finish which is acceptable to the cottom system for textile processing without further treatment.

These and other objects will become apparent in the course of the following specification and claims.

In accordance with a preferred embodiment of the present invention, a synthetic textile fiber is provided with durable antistatic properties by continuously associating the fiber during the spinning thereof with an aqueous polyamine/epoxy composition which also contains a third ingredient. The polyamine/epoxy molecule carries a plus charge due to the presence of a quaternary ammonium group on the end thereof. This aids the oxygen and nitrogen atoms, which are present in the long-chain molecule, in the conduction of static electrical charges. The third ingredient mentioned prevents the filaments from sticking together during the spinning thereof and from adhering to the textile machinery.

The use of these antistatic agents, in accordance with the present invention, effects improvements in the characteristics of acrylonitrile polymers and articles produced therefrom. The invention is applicable not only to polyacrylonitrile, but also to copolymers, interpolymers and blends thereof, particularly those containing at least percent by weight of polymerized or copolymerized acrylonitrile. Such polymeric materials include acrylonitrile fiber-forming polymers with readily dyeable basic copolymers, the blend having an overall polymerized acrylonitrile content of at least 80 percent by weight.

For example, the polymer may be a copolymer of from 80 to '98 percent of acrylonitrile and from 2 to 20 percent of another copolymerizable mono-olefinic monomer. Suitable copolymerizable mono-olefinic monomers include acrylic, alphachloroacrylic and methacrylic acids, the acrylates, such as methylmethacrylate, ethylmethacrylate, butylmethacrylate, methoxymethyl methacrylate, beta-chloroethyl methacrylate, and the corresponding esters of acrylic and .alpha-chloroacrylic acids; vinyl chloride, vinyl fluoride, vinyl bromide, vinylidene chloride, 1- chloro 1 bromoethylene; methacrylonitrile; acrylamide and methacrylarnide; alpha-chloroacrylamide, or monoalkyl substitution products thereof; methyl vinyl ketone; vinyl carboxylates, such as vinyl acetate, vinyl chloroacetate, vinyl propionate, and vinyl stearate; N-vinylimides, such as N-vinylphthalimide and N-vinylsuccinimide; methylene malonic esters; itaconic acid and itaconic ester; N-vinyl carbazole; vinyl furane; alkyl vinyl esters; vinyl sulfonic acid; ethylene alpha, beta-dicarboxylic acids or their anhydrides or derivatives, such as diethylcitraconate, diethylmesaconate; styrene; vinyl naphthalene; vinyl-substituted teritiary heterocyclic amines such as the vinylpyridines and alkyl-substituted vinylpyridines for example, 2-vinylpyridine, l-vinylpyridine, 2-methyl-5- vinylpyridine, and the like; l-vinylimidazole and .alkylsubstituted l-vinylimidazoles, such as 2-, 4-, or S-methyll-vinylimidazole, vinylpyrrolidone, vinylpiperidone, and other mono-olefinic copolymerizable monomeric materials.

The polymer can be a ternary interpolymer for example, products obtained by the interpolymerization of acrylonitrile and two or more of any of the monomers, other than acrylonitrile, enumerated above. More specifically, and preferably, the ternary polymers contain from 80 to 98 percent of acrylonitrile, from 1 to 10 percent of a vinylpyridine or a l-vinylimidazole, and from 1 to 18 3 percent of another copolymerizable mono-olefinic substance, such as methacrylonitrile, vinyl acetate, methylmethacrylate, vinyl chloride, vinylidene chloride, and the like.

The polymer can also be a blend of polyacrylonitrile or a copolymer of from 80 to 99 percent acrylonitrile and from 1 to 20 percent of at least one other mono-olefinic copolymerizable monomeric substance with from two to fifty percent of the weight of the blend of a copolymer of from 30 to 90 percent of a vinyl substituted tertiary heterocyclic amine and from to 70 percent of at least one other mono-olefinic copolymerizable monomer. Preferably, when the polymeric material comprises a blend, it will be a blend of from 80 to 99 percent of a copolymer of 80 to 98 percent acrylonitrile and from 2 to precent of another mono-olefinic monomer, such as vinyl acetate, which is not receptive to dyestutf, with from 1 to 20 percent of a copolymer of from 30 to 90 percent of a vinyl-substituted tertiary heterocyclic amine such as a vinylpyridine, a l-vinyiimidazole, or a vinyl lactam, and from 10 to 70 percent of acrylonitrile to give a dyeable blend having an overall vinyl-substituted tertiary heterocyclic amine content of from 2 to 10 percent, based on the weight of the blend.

While the preferred polymers employed in the instant invention are those containing at least 80 percent acrylonitrile, generally recognized as the fiber-forming acrylonitrile polymers, it will be understood that the invention is likewise applicable to polymers containing less than 80 percent of acrylonitrile. Polymers containing less than 80 percent acrylonitrile are useful in forming fibers, lacquers, coating compositions and molded articles.

Such a fiber may be formed by extruding a typical acrylonitrile-based spinning dope through a conventional spinnerette into an aqueous coagulation bath wherein the dope hardens into a filament. After the fibers were washed and stretched as they were drawn up a hot water cascade, they were heated and partially dried on a set of drying rolls. When the moisture content of the fiber was from 10 to 50 percent by weight and the temperature of the filaments has reached approximately 100 C., they are immersed in an aqueous emulsion which contains.

(a) a polyamine, (b) an epoxy resin, and (c) an aliphatic ester of a fatty acid.

These three ingredients are described in more detail hereinafter. The mixture preferably also contains a dispersing or emulsifying agent which insures a more homogeneous suspension of the several ingredients and, because of the reactive nature of these ingredients, it is preferably held at temperatures below about 40 C. in order to prevent premature polymerization and thus extend the useful pot life of the mixture. The treated fibers then continue through a series of heated rolls during which time the fibers are completely dried and the antistatic coating is polymerized by the heat from the rolls thereby forming a veneer around the fibers. The time required for a segment of fiber to complete its course through the dual series of heated rolls and the application bath is approximately 30 to 60 seconds. This is approximately the length of time required for treating the fiber with the antistatic emulsion and for making the same water insoluble. After the fiber has been dried, if desired, it may be crimped, relaxed in a steam atmosphere, recrimped if desired, and cut to any desired staple length. The product is now ready for textile processing without the application of any further textile finishing ingredients.

In accordance with the present invention, this antistatic agent may also be used in combination with other textile filaments, such as polyester fibers and articles produced therefrom. A fiber was formed by extruding a typical polyester melt, such as polyethylene terephthalate, through a conventional spinnerette downwardly through a chimney where the melt was air quenched and was hardened into filaments. The fibers were converged and collected on a bobbin as undrawn yarn. A number of bobbins were then combined and a tow was formed by continuously pulling the yarn therefrom. The tow was heated to at least 40 C. by being passed under a hot water spray. The fiberous tow then passed into a draw zone where the temperature thereof was increased to C. C. by another hot water spray or by a finishing solution and was elongated from four to five times its original length. After the tow has been drawn, it was immersed in or sprayed with an aqueous antisatic emulsion which becomes polymerized thereon when heated on the drying rolls to about 145 C. The dried fibrous tow was then cut to staple lengths and processed according to conventional techniques.

While this invention has been generally directed to its use on acrylic fibers the antistatic finish is especially useful on fibers formed from a polyamide. Simple linear polyamides which are normally insoluble in alcohol but are soluble in phenols and they are of two types, hose derived from polymerizable monoaminomonocarboxylic acids or their amide forming derivatives and those derived from the reaction of a suitable diamine with suitable dicarboxylic acids. On hydrolysis with mineral acids, the polyamides yield monomeric amide forming reactants. The activating compounds of this invention are applicable to the polycarbonamides of the type derived from the reaction of a suitable diamine with a suitable dicarboxylic acid. On hydrolysis with hydrochloric acid, these polycarbonamides yield the dibasic acid and the diamine hydrochloride. These polycarbonamides are of the general type disclosed in US. Patents 2,071,250, 2,071,253 and 3,130,948. The term polycarbonamide means polymers having recurring units of formula:

where R is hydrogen or a monovalent hydrocarbon radical as integral parts of the main polymer chain, the average number of carbon atoms separating the amide groups being at least two.

In particular, this invention is concerned with the simple, unsubstituted polyamides such as the polymers formed by the reaction of tetramethylene diamine and adipic acid, tetramethylenediamine suberic acid, tetramethylenediarnine with sebacic acid, hexamethylenediamine with adipic acid, hexamethylenediamine with suberic acid and hexamethylenediamine with sebacic acid. Broadly, this invention will cover any nylon formed from a diamine and a dicarboxylic acid as well as those formed from the interpolymerization of monoaminomonocarboxylic acid. In addition, polymers formed from the reaction or two or more diamines are contemplated. Thus, the word polyamide is defined as above for the purpose of this invention and when referred to in the specification encompasses the above monoaminomonocarboxylic acid polyamide as well as the diamine-diacid polyamides.

The permanency of the antistatic coating which has been applied to the fibers was checked in the following manner. The fibers are converted into yarn and the yarn is knitted into a tubular fabric shape. The fabric is then washed in a Kenmore washing machine at F. using a 0.5 percent aqueous solution Tide detergent for four minutes or alternatively, a 0.3 percent solution of tetra sodium pyrophosphate may be used as the detergent. After the tube is removed from the Washing machine, it is centrifuged to remove the excess moisture. The steps of washing the tube in the detergent for four minues and centrifuging it are repeated four times whereupon it is dried in an air atmosphere with a relative humidity of 35 percent at a temperature of 72 F. The tube is then run on a Hayeck and Chromey apparatus to determine the level of static protection. The protection is considered satisfactory if one-half of the static electrical charge induced thereon is drained off within 60 seconds.

wherein n is a Whole integer from 2 to 40, X is selected from the group consisting of Cl and NHCH R is a whole number from about 30 to about 100 and q is a whole number from about 4 to about 14. Where the above structure contains a covalent chlorine end group, it is contemplated that it could react further with a secondary or tertiary amine group to form a still more complex structure. The preparation of these polyamines is discussed in U.S. Patent No. 3,070,552 to Tesoro, granted .Dec. 25, 1962. In general, polyethylene glycol 600 is reacted with thionyl chloride to form polyethylene glycol 600 dichloride. The latter is extended with monoethyl amine so that both active hydrogens react and two molecules of HCl are split out. The final mechanism for crosslinking the finish to render it permanent by reaction with an epoxide is assumed to proceed through the hydrogen of the secondary amine. A commercially available polyamine useful with the invention is Aston 1022.

The epoxide referred to above can be prepared by condensing epichlorohydrin with a polyol. A typical example is the condensation product (with elimination of HCl) of glycerine and epichlorohydrin. Preparation of these products is described in detail in British Patent 780,288, dated July 31, 1957. Such a material with a molecular weight of between about 230 to 360 is available on the open market under the trademark Eponite 100 (viscosity 90-150 cp. at 25 C.; 10.2 lb./gal.). Other similar commercial products from the same source include the Epon resins, which are diepoxide condensation products of epichlorohydrin and 2,2-diphenylol propane, and the poly (allyl glycidyl ethers).

The third critical ingredient of this finishing composition was selected from the group consisting of partial fatty acid esters of polyhydroxy compounds. Particularly preferred among such ingredients are fatty acid mono and diglycerides and mixtures containing such glycerides. A convenient source of such glycerides are the mixtures of mono-, di-, and triglycerides prepared simultaneously with sodium soap emulsifiers as discussed and defined in the examples and claims of US. Patent 2,978,408 (with particular reference to the fourth full paragraph of column 2), currently under the trademark Proxoft N, which in addition to the above compounds also contains a heat labile acid salt and an additional emusifying agent which are not important to the instant invention. An example of an aliphatic ester in accordance with the present invention is a fatty glyceride of the formula:

wherein --(M)-- is a hydrogen atom or fatty acid residue of the formula and --R-- is an alkyl group containing from 13 to 21 carbon atoms.

A dispersing agent is preferably added to the polyamine/epoxy/ fatty glyceride mixture to insure a thorough mixture of the respective ingredients. Satisfactory dispersing agents are the aromatic polyglycol ethers, one example of such being the alkylphenol polyglycol ether containing 9.5 moles of ethylene oxide which can be purchased on the open market under the trademark Neutronyx 600. Another example of such a dispensing agent is nonylphenoxy poly(ethyleneoxy) ethanol which may be purchased under the trade name Igepal. Another satisfactory dispersing agent is nonylphenyl polyethylene glycol ether which can be purchased on the open market under the trade name, Tergitol.

The following examples are cited to illustrate the invention. They are not intended to limit this invention in any way. Unless otherwise noted, parts are expressed in the examples indicate parts by weight.

Example I An acrylic fiber consisting of a copolymer of 93 percent acrylonitrile and 7 percent vinyl acetate was wet spun in a conventional manner. Prior to the final drying of the coagulated, washed and partially collapsed fiber, it was passed through a bath comprising an aqueous emulsion as described below, the concentration thereof being adjusted to afford a solids pickup of 0.50 percent based on the weight of the dried fiber. The concentration of the finish solution based on the weight of the constituents was as follow:

Finish solution, percent Aston 1022 5.00

ProxoftN 1.33 Eponite 100 0.63 Neutronyx 600 0.014

A fabric sample prepared from the treated staple had a static half-life of 2 seconds after it had been washed 10 times and 3 seconds after it had been washed 20 times in a 0.5 percent solution of "Tide" detergent.

Example II An acrylic fiber consisting of percent acrylonitrile, 7 percent vinyl acetate, and 7 percent 2-methyl-5-vinylpyridine was wet spun according to conventional techniques and the finish was applied as described in Example I. The concentration of the finished solution based on the weight of the constituents was:

Finish solution, percent Aston 1022 2.5 Eponite 0.32 Neutronyx 600 0.007 Proxoft N 0.66

The textile processing characteristics of the staple fiber Were good. A fabric sample which Was prepared from the finished staple fiber had a static half-life of 4 seconds after 10 washings and 5 seconds after 20 washings in a 0.5- percent solution of Tide detergent.

Example III A polyethylene terephthalate fiber was melt spun and processed into staple according to conventional procedures. Prior to the final drying operation, the tow was sprayed with a finish solution prepared as described in Example I. The finished staple processed Well through the textile system. A fabric sample prepared from the staple had a static half-life of 18 seconds after 10 washings and a 43 seconds after 20 washings in a 0.5 percent solution of Tide detergent.

Example IV A polyethylene terephthalate fiber was melt spun and processed into staple according to conventional procedures. Prior to the final drying operation, the tow was sprayed with a finish solution prepared as described in Example II. The finished staple processed well through the textile system. A fabric sample prepared from the staple had a static half-life of 20 seconds after 10 washings and a 47 seconds after 20 washings in a 0.5 percent solution of Tide detergent.

Example V Example VI A polyamide fiber was melt spun and processed into staple according to conventional procedures. Prior to the final drying operation, the tow was sprayed with a finish solution prepared as described in Example II. The finished staple processed well through the textile system. A fabric sample prepared from the staple had a static half-life of 1 second after 10 washings and a 6 seconds after 20 washings in a 0.5 percent solution of Tide detergent.

Many different modifications of the invention may be made without departing from the scope and spirit thereof. It is contemplated that variations may be made in the percentage of the compounds used without greately altering the antistatic characteristics of the fiber; therefore, the applicant does not wish to be bound by the numbers exactly as they appear above.

We claim:

1. A composition of matter useful for minimizing the accumulation of charges of static electricity on synthetic textile fibers, said composition comprising the reaction product of:

(a) a polyepoxide,

(b) a polyamine of the formula:

wherein n is a whole integer from 2 to 40, X is selected from the group consisting of chlorine and -NHCH r is a whole number from about 30 to about 100, and q is a whole number from about 4 to about 14, and

(c) a fatty glyceride.

2. A composition of matter useful for minimizing the accumulation of charges of static electricity on synthetic textile fibers, said composition comprising the reaction product of:

(a) a polyepoxide,

(b) a polyamine of the formula:

wherein n is a whole integer from 2 to 40, X is selected from the group consisting of chlorine and --NHCH r is a whole number from about 30 to about 100 8 and q is a whole number from about 4 to about 14, (c) a mixture of mono-, di-, and triglycerides of the formula: n

crno-oR CHO(M) CHz-O-(M) 10 where (M) is selected from the group consisting of a hydrogen atom and a fatty acid residue of the formula:

0 ll R wherein -R is an alkyl group containing from about 13 to about 21 carbon atoms. 3. A process of minimizing the accumulation of charges of static electricity upon a hydrophobic shaped structure comprising applying to said structure a mixture of:

(a) a polyepoxide, (b) a polyamine of the formula:

(EH3 XOH OHAOCHzCI-Ig)[N(CHgCH O)uCHaCH;],

Y III-CHzCHKO CHzCHz) 1:

wherein n is a whole integer from 2 to 40, X is selected from the group consisting of chlorine and --NHCH r is a whole number from about to about 100 and q is a whole number from about 4 to about 14,

(c) a fatty glyceride,

and polymerizing said mixture on said structure.

4. The process of claim 3 wherein said mixture is in the form of an aqueous emulsion.

5. A process of minimizing the accumulation of charges of static electricity upon a synthetic textile filament comprising applying to said filament a mixture in the form of an aqueous emulsion consisting of (a) a polyepoxide,

(b) a polyamine of the formula:

wherein (M) is selected from the group consisting of a hydrogen atom and a fatty acid residue of the formula:

wherein -R is an alkyl group containing from about 13 to about 21 carbon atoms, and polymerizing said mixture on said filament.

6. The process of claim wherein the textile filament is a copolymer consisting of about 93 percent acrylonitrile and 7 percent vinyl acetate.

7. The process of claim 5 wherein the textile filament is a polyester.

8. The process of claim 5 wherein the textile fiber is a terpolymer consisting of about 86 percent acrylonitrile, 7 percent vinyl acetate and 7 percent 2-methyl-5-vinylpyridine.

9. The process of claim 5 wherein the textile filament is formed from a polyamide.

10. A process of minimizing the accumulation of charges of static electricity on a synthetic textile filament comprising contacting the filament during the spinning thereof with an aqueous emulsion consisting essentially of (a) a polyepoxide,

(b) a polyamine of the formula wherein n is a whole integer from about 2 to about 40, X is selected from the group consisting of chlorine and NHCH r is a Whole numher from about 30 to about 100 and q is a whole number from about 4 to about 14, and

(c) a mixture of mono-, di-, and triglycerides of the formula:

oHlo- R CH-O-(M) CHr-o-(M) wherein (M) is selected from the group consisting of a hydrogen atom and a fatty acid residue of the formula:

i CR wherein R is an alkyl containing from about 13 to about 21 carbon atoms, and heating the filament to cure the emulsion on said filament.

11. The process of claim 10 wherein the synthetic textile filament is selected from the group consisting of a polyamide fiber, a polyester fiber, and an acrylonitrile polymer containing fiber.

12. The process of claim 10 wherein the temperature of the aqueous emulsion is up to about C.

13. The process of claim 10 wherein the polyepoxide is a condensation product of epichlorohydrin and a polyol. 14. A synthetic textile fiber treated by the process of claim 10.

15. A polyamide fiber treated by the process of claim 10.

16. A polyester fiber treated by the process of claim 10. 17. An acrylonitrile polymer containing fiber treated by the process of claim 10.

References Cited UNITED STATES PATENTS 2,735,790 2/1956 Waitkus 117139.5 2,978,408 4/1961 Lanner et al. 252-8.6 3,070,552 12/1962 Tesoro et al. 260--2.1

FOREIGN PATENTS 780,288 7/ 1957 Great Britain.

DONALD E. CZAJ A, Primary Examiner.

R. W. GRIFFIN, Assistant Examiner. 

1. A COMPOSITION OF MATTER USEFUL FOR MINIMIZING THE ACCUMULATION OF CHARGES OF STATIC ELECTRICITY ON SYNTHETIC TEXTILE FIBERS, SAID COMPOSITION COMPRISING THE REACTION PRODUCT OF: (A) A POLYEPOXIDE, (B) A POLYAMINE OF THE FORMULA: 